Oyem Solar Power Station in Gabon: 50MW Solar PV Project Cable Design & Electrical Configuration (2023–2024)

When a Johannesburg-based renewable energy developer secured the EPC contract for Gabon's 50MW Oyem Solar Power Station in early 2023, they faced a procurement challenge that would make or break the entire project. The site in northern Gabon's Woleu-Ntem region demanded cable infrastructure spanning three voltage tiers and eight distinct technical specifications—all requiring IEC certification, tropical climate resilience, and delivery within an 18-month construction window that brooked no delay.

The developer had learned hard lessons from previous African projects. European suppliers offered impeccable certificates but unpredictable lead times. Local procurement promised speed but couldn't guarantee the EN 50618 and IEC 62930 compliance demanded by international lenders. They needed something rarer: a manufacturer combining certified quality with project-responsive logistics and technical depth.

That search led them to Dongguan GERITEL Electrical Co., Ltd.

The Technical Landscape

The Oyem project's electrical architecture demanded integrated cable supply across every power zone. In the photovoltaic field, over 800 kilometers of H1Z2Z2-K cables would connect tens of thousands of panel strings. Specifically, we supplied H1Z2Z2-K 1×4mm² as the primary specification—this single-core 4mm² cross-section cable employs tin-plated copper conductors with IEC 60228 Class 5 ultra-fine stranding, paired with electron-beam cross-linked dual-layer halogen-free polyolefin insulation, achieving 1500V DC continuous rating and 1800V surge capacity. For longer string connections, we also provided H1Z2Z2-K 1×6mm² specification, where the larger 6mm² cross-section effectively reduces line resistance, significantly cutting power losses across string lengths exceeding 800 meters. These cables' AD8 water resistance rating and -40°C to +120°C operational temperature range were specifically engineered for Gabon's tropical climate.

Between inverter stations and the 33kV substation, YJV power cables formed the low-voltage AC collection network. Specific specifications included YJV 4×240mm²—this four-core 240mm² cross-section cross-linked polyethylene insulated cable features compacted circular copper conductor stranding, 90°C-rated XLPE insulation, and weather-resistant PVC outer sheath, capable of withstanding harmonic currents at inverter outputs and outdoor exposure. For shorter feeder circuits, we selected YJV 4×70mm² specification, where the 70mm² cross-section balanced cost and current-carrying capacity, with the four-core configuration's full-size neutral supporting modern inverter three-phase four-wire topology.

The medium-voltage side employed 33kV XLPE cables for power transmission from step-up transformers to grid connection points. Specific models included 33kV XLPE 3×185mm² specification—three-core 185mm² cross-section with circular compacted copper conductor stranding, triple-extruded cross-linked polyethylene insulation, semi-conductive shielding layers ensuring uniform electric field distribution, and metallic shielding using copper wire braiding that accommodates both earth fault current capacity and radial water-blocking functionality. For shorter medium-voltage feeders, we provided 33kV XLPE 3×70mm² specification, where the 70mm² cross-section met current-carrying requirements while optimizing material costs.

External grid connection infrastructure needed to withstand mechanical stress from direct burial installation. We supplied YJV 4×400mm² as the non-armored option—four-core 400mm² cross-section ultra-high-capacity design with single-core conductor diameter exceeding 23mm, satisfying the full power output requirements of a 50MW station. For sections crossing roads and excavation-prone areas, we employed SWA 4×400mm² armored specification—adding double-layer galvanized steel wire armor over standard YJV construction, with 2.5mm wire diameter and optimized lay pitch that provides compression crush protection while maintaining appropriate bending performance for installation.

Control infrastructure precision wiring was equally critical. Inside inverter rooms, H07V-K 16mm² specification handled connections between main power terminals and circuit breakers—16mm² cross-section single-core flexible design with ultra-fine copper wire conductor stranding, 1.2mm PVC insulation thickness, and 450/750V rating, enabling reliable high-current transmission within cramped cabinet spaces. For signal circuits, we deployed H05VV-F 5×10mm² specification—five-core 10mm² cross-section multi-core flexible cable with central reinforcing core structure for superior tensile performance, and oil-resistant abrasion-resistant special PVC sheath, suitable for SCADA system and inverter control signal centralized wiring.

Why Certification Architecture Mattered

The developer's financing package required TÜV Rheinland-certified manufacturing. This wasn't box-checking—it was risk mitigation. Any cable failure in the 800km PV field would mean locating and replacing a fault under 50MW of installed capacity, with downtime costs dwarfing the original material price.

GERITEL's vertical integration proved decisive. Our electron beam cross-linking equipment, in-house conductor drawing, and unified quality management meant the H1Z2Z2-K 1×4mm² supplying string connections and the 4×400mm² SWA feeding the main transformer shared identical raw material specifications and testing protocols. TÜV surveillance audits cover every production stage, not just final inspection.

The H1Z2Z2-K designation itself carried weight. Unlike legacy PV1-F cables or discontinued ZZ-F products, true EN 50618-compliant H1Z2Z2-K achieves 1500V DC continuous rating with 1800V surge capacity, AD8 water resistance, and -40°C to +120°C operational range. For the Oyem site, this translated to conservative engineering margins that reduce long-term degradation risks and satisfy insurer requirements.

Logistics as Engineering

The 18-month construction timeline demanded phased delivery aligned with civil works progress. We structured supply in five waves: control cables for early building construction, H1Z2Z2-K field cables synchronized with panel mounting, power cables for inverter station build-out, and heavy infrastructure cabling for final grid connection.

This sequencing minimized on-site storage in Gabon's humid climate and eliminated the cascading delays that plague poorly coordinated projects. When unexpected installation damage occurred to one 4×240mm² YJV batch, our technical team's 48-hour response—replacement shipment plus field guidance—prevented schedule slippage that would have triggered liquidated damages.

Operational Validation

As the Oyem station approached commercial operation in early 2024, commissioning tests validated the cable infrastructure. String-level monitoring showed minimal DC resistance variation across the H1Z2Z2-K 1×4mm² network, ensuring balanced current collection and maximum power point tracking efficiency. Medium-voltage testing confirmed the 33kV XLPE 3×185mm² insulation integrity under full load simulation.

The project now stands as Central Africa's largest solar installation, feeding 50MW of clean capacity into Gabon's grid. For the developer, successful cable procurement has established GERITEL as preferred supplier for their expanding regional portfolio.

Your Project Deserves Equivalent Certainty

Cable selection in utility-scale solar isn't about meeting minimum specifications—it's about engineering margin that protects 25-year revenue streams. The H1Z2Z2-K 1×4mm² chosen for Oyem wasn't the cheapest option available; it was the option that eliminated technical risk from the project's critical path.

GERITEL delivers this certainty through certified manufacturing depth, project-specific logistics coordination, and technical support that extends beyond delivery to successful commissioning. Whether your development is 5MW distributed or 100MW+ utility-scale, our cable engineering team translates electrical specifications into reliable infrastructure.

Dongguan GERITEL Electrical Co., Ltd. Full IEC 62930 / EN 50618 / TÜV certification | Factory-direct supply | Integrated quality from H07V-K to 33kV XLPE

Tel/WhatsApp/WeChat: +86 135 1078 4550 / +86 136 6257 9592

Email: manager01@greaterwire.com